Though they are virtually unknown to Americans, "The Krays" were the most notorious gangsters in the history of England, and this movie about them is guaranteed to chill audience members to the bone.

Twin brothers Ronald and Reginald Kray, played by Gary and Martin Kemp (best known as musicians with the rock group Spandau Ballet), were racketeers who ruled London's East End during the 1950s and '60s.

The film begins with their childhood, where the Kray brothers develop a special "twin" relationship, a sort of psychic attachment that allows them to feel each other's wavelength and understand each other even when nothing is expressed verbally.

This is something often attributed to twins, but in this instance it's an instrument for evil. That's not a new movie concept, but it's all the more disturbing here for being based on a true story.

As they grow older, with a propensity toward criminal activity and causing pain to those who cross them, Reggie seems to have a desire to pull away and go straight on occasion — especially after he marries his true love. But Ronnie has a hold over him and steers him toward the worst of his instincts.

As much as a portrait of their reign of blood and terror over London's East End, however, the film is also about their relationship with their loving, if naive mother, Violet, played by veteran British actress Billie Whitelaw.

Violet loves her sons so much she is unwilling to believe the newspapers, the talk about town or even what she sees with her own eyes. And she is very much a hands-on, take-charge woman whose husband is a bit of a wimp.

The relationships between the two brothers and between them and their mother are the primary focus of the film, but there is also a revealing look at how crime in Great Britain changed once the Krays took over.

As they grow up and observe the rackets, Ronnie and Reggie take them over by sheer brute force. They are nastier than anyone else so everyone wants to stay out of their way.

Initially it is their arrogance that puts them on top, but, of course, it is also that arrogance that eventually causes their downfall.

It's a fascinating story, with shocking bursts of violence — two scenes in particular — that are gruesome and may be off-putting to some of the film's potential audience.

Despite the filmmakers' obvious feeling that the violence was necessary in context, it gets so gory at times that it seems a bit gratuitous.

But in general the script, direction and performances are solid, with especially good turns by the Kemp brothers as the Kray brothers and Whitelaw as their mother.